| Message ID | 20160923130907.4187-2-lorenzo.pieralisi@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 23 Sep 2016, Lorenzo Pieralisi wrote: > The CCI ports programming interface is available to the kernel > only when booted in secure mode (or when firmware enables > non-secure access to override CCI ports control). In both cases, > firmware reports the CCI ports availability through the device > tree CCI ports nodes, which must be parsed and their status checked > by the kernel probing path. > > This check is currently missing and may cause the kernel to > erroneously believe it is free to take control of CCI ports > where in practice CCI ports control is forbidden. > > Add the missing CCI port availability check to the CCI driver > in order to guarantee sane CCI usage. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Liviu Dudau <liviu.dudau@arm.com> > Cc: Sudeep Holla <sudeep.holla@arm.com> > Cc: Nicolas Pitre <nicolas.pitre@linaro.org> > Cc: Suzuki K Poulose <suzuki.poulose@arm.com> > Cc: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> > --- > drivers/bus/arm-cci.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c > index 5755907f..3c7a1c7 100644 > --- a/drivers/bus/arm-cci.c > +++ b/drivers/bus/arm-cci.c > @@ -2199,6 +2199,9 @@ static int cci_probe_ports(struct device_node *np) > if (!of_match_node(arm_cci_ctrl_if_matches, cp)) > continue; > > + if (!of_device_is_available(cp)) > + continue; > + > i = nb_ace + nb_ace_lite; > > if (i >= nb_cci_ports) > @@ -2241,6 +2244,13 @@ static int cci_probe_ports(struct device_node *np) > ports[i].dn = cp; > } > > + /* > + * If there is no CCI port that is under kernel control > + * return early and report probe status. > + */ > + if (!nb_ace && !nb_ace_lite) > + return -ENODEV; > + > /* initialize a stashed array of ACE ports to speed-up look-up */ > cci_ace_init_ports(); > > -- > 2.10.0 > >
diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c index 5755907f..3c7a1c7 100644 --- a/drivers/bus/arm-cci.c +++ b/drivers/bus/arm-cci.c @@ -2199,6 +2199,9 @@ static int cci_probe_ports(struct device_node *np) if (!of_match_node(arm_cci_ctrl_if_matches, cp)) continue; + if (!of_device_is_available(cp)) + continue; + i = nb_ace + nb_ace_lite; if (i >= nb_cci_ports) @@ -2241,6 +2244,13 @@ static int cci_probe_ports(struct device_node *np) ports[i].dn = cp; } + /* + * If there is no CCI port that is under kernel control + * return early and report probe status. + */ + if (!nb_ace && !nb_ace_lite) + return -ENODEV; + /* initialize a stashed array of ACE ports to speed-up look-up */ cci_ace_init_ports();
The CCI ports programming interface is available to the kernel only when booted in secure mode (or when firmware enables non-secure access to override CCI ports control). In both cases, firmware reports the CCI ports availability through the device tree CCI ports nodes, which must be parsed and their status checked by the kernel probing path. This check is currently missing and may cause the kernel to erroneously believe it is free to take control of CCI ports where in practice CCI ports control is forbidden. Add the missing CCI port availability check to the CCI driver in order to guarantee sane CCI usage. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> --- drivers/bus/arm-cci.c | 10 ++++++++++ 1 file changed, 10 insertions(+)